Design, Construction and Operation of the New CERN SC RF System

Abstract

A fast cycling RF-system giving high energy-gain per revolution was required to overcome the intensity limitations set by space-charge in the CERN SC. All other frequency modulation methods being discarded for power reasons, a high Q system tuned by a rotary capacitor was chosen.

The rotary capacitor, constituing the most critical part, requires excellent vacuum, forced cooling on all RF electrodes and high mechanical precision. The mechanical problems which, in the early stage of the design, were feared most, proved to be solvable. However, considerable effort was necessary to obtain sufficient reliability of vacuum and cooling circuits. Specially shaped stator blades are used to furnish an optimized frequency modulation programme.

The RF circuit design by means of models and computer programmes was initiated at first at CERN and continued later by industry. Detail hardware design and construction was performed by industry, further development and running-in by CERN.

The system is performing satisfactorily and has permitted acceleration of the design proton intensity per machine pulse.